diff --git a/tools/unix/translate_categories.sh b/tools/unix/translate_categories.sh
index 1c22805307..2fff4e836f 100755
--- a/tools/unix/translate_categories.sh
+++ b/tools/unix/translate_categories.sh
@@ -1,6 +1,12 @@
 #!/bin/bash
 
-set -e -u
+# Install translate-shell before using this script.
+# Use `brew install translate-shell` on Mac OS X.
+
+# There is a rate-limit for Google which can be work-arounded by using
+# another IP or IPv6.
+
+set -euo pipefail
 
 case $# in
   1) SRC=en
@@ -9,22 +15,24 @@ case $# in
   2) SRC="$1"
      WORD="$2"
      ;;
-  *) echo "Usage: $0 word_in_English"
+  *) echo "Usage: $0 word_or_text_in_English"
      echo "       or"
-     echo "       $0 language_code word_in_given_language"
+     echo "       $0 source_language_code word_or_text_in_given_language"
      exit 1
      ;;
 esac
 
-LANGUAGES=( en ar cs da de el es fi fr he hu id it ja ko nb nl pl pt ro ru sk sv sw th tr uk vi zh-CN zh-TW )
+# Note: default Google engine doesn't properly support European Portuguese (pt-PT)
+# and always produces Brazilian translations.
+LANGUAGES=( en ru ar be bg cs da de el es fa fi fr he hu id it ja ko nb nl pl pt-PT pt-BR ro ru sk sv sw th tr uk vi zh-CN zh-TW )
 
 for lang in "${LANGUAGES[@]}"; do
   TRANSLATION=$(trans -b "$SRC:$lang" "$WORD" | sed 's/   *//')
-  # Use our categories.txt names for Chinese.
-  if [[ $lang == "zh-CN" ]]; then
-    lang="zh-Hans";
-  elif [[ $lang == "zh-TW" ]]; then
-    lang="zh-Hant";
-  fi
+  # Correct language codes to ours.
+  case $lang in
+    zh-CN) lang="zh-Hans" ;;
+    zh-TW) lang="zh-Hant" ;;
+    pt-PT) lang="pt"      ;;
+  esac
   echo "$lang:$(tr '[:lower:]' '[:upper:]' <<< ${TRANSLATION:0:1})${TRANSLATION:1}"
 done